A magnitude 4.4 quake struck at 11:20 a.m., with its epicenter located 19.6 kilometers southeast of Yilan County Hall at a depth of 7.5 km.
It was followed by another 4.4 magnitude shake one minute later, which had its epicenter 18.5 km southeast of county hall at a depth of 10.1 km.
The third temblor occurred at 12:29 p.m. with a magnitude of 5.5. Its epicenter was 25 km southeast of Yilan County Hall at a depth of 16.4 km., with the highest intensity detected in Yilan's Nan'ao at five.
The intensity in Yilan City and Hualien's Heping reached four, and that in New Taipei and Taipei was recorded at three.
Ten minutes later, a magnitude-4 quake shook eastern Taiwan again. Its epicenter was 22.4 km east of Yilan County Hall at a depth of 12.4 km, according to CWB data.
These were all aftershocks from the magnitude 5.8 earthquake that struck at 11:17 a.m., the CWB's Seismic Information Center said. (By Elizabeth Hsu)jc